Support for providing media stream audio track to speech recognition

Source/modules/speech/SpeechRecognition.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 35 matching lines @@
 
 void SpeechRecognition::start(ExceptionState& exceptionState)
 {
     ASSERT(m_controller);
     if (m_started) {
         exceptionState.throwDOMException(InvalidStateError, "recognition has already started.");
         return;
     }
 
     m_finalResults.clear();
+    m_controller->attach(this, m_audioTrack);
     m_controller->start(this, m_grammars.get(), m_lang, m_continuous, m_interimResults, m_maxAlternatives);

[no longer working on chromium, 2014/08/15 10:22:56]

I am wondering if we should just pass the m_audioTrack in the start method. Lets
get Glen's opinion on this.

[burnik, 2014/08/15 11:29:41]

I've gone through that approach as well, and in order to follow the same path as
rest of the params, we would have to add the audio track to
WebSpeechRecognitionParams. That looks a bit messy and out of place to me. I
think it's cleaner this way since the audio track is an extension to existing
behaviour and all other params are API related, while m_audioTrack is not.

However, I do agree, Glen should help us decide.

On 2014/08/15 10:22:56, xians1 wrote:

     m_started = true;
 }
 
 void SpeechRecognition::stopFunction()
 {
     ASSERT(m_controller);
     if (m_started && !m_stopping) {
         m_stopping = true;
         m_controller->stop(this);
     }
@@ skipping 94 matching lines @@
 }
 
 bool SpeechRecognition::hasPendingActivity() const
 {
     return m_started;
 }
 
 SpeechRecognition::SpeechRecognition(ExecutionContext* context)
     : ActiveDOMObject(context)
     , m_grammars(SpeechGrammarList::create()) // FIXME: The spec is not clear on the default value for the grammars attribute.
+    , m_audioTrack(nullptr)
     , m_continuous(false)
     , m_interimResults(false)
     , m_maxAlternatives(1)
     , m_controller(nullptr)
     , m_stoppedByActiveDOMObject(false)
     , m_started(false)
     , m_stopping(false)
 {
     ScriptWrappable::init(this);
     Document* document = toDocument(executionContext());
 
     Page* page = document->page();
     ASSERT(page);
 
     m_controller = SpeechRecognitionController::from(page);
     ASSERT(m_controller);
 
     // FIXME: Need to hook up with Page to get notified when the visibility changes.
 }
 
 SpeechRecognition::~SpeechRecognition()
 {
 }
 
 void SpeechRecognition::trace(Visitor* visitor)
 {
     visitor->trace(m_grammars);
+    visitor->trace(m_audioTrack);
 #if ENABLE(OILPAN)
     visitor->trace(m_controller);
 #endif
     visitor->trace(m_finalResults);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace blink